Dysphagia is difficulty in the process of swallowing food from the mouth to the stomach. Recently, the definition was expanded to all acts and sense related to swallowing and preliminary act to prepare swallowing.
Dysphagia can occur in all ages from a newborn infant to an old man and can be a result of various congenital deformity or structural damage or medical state. (Lazarus & Logemann, 1987; Logemann, 1989; Veis & Logemann, 1985). Further, pleasure of eating or maintenance of nutrition and hydration can be interrupted in terms of function due to dysphagia (Buchhloz, 1996). Normally ingesting food with mouth is not only basic means of maintaining life but also important in leading a high quality of life.
There are various causes for dysphasia such as minor causes like simple anomaly in teeth or prostheses and other nerve diseases such as stroke and etc. due to nerve paralysis causing paralysis of muscle of mouth, pharynx and esophagus, and constricta with narrowed pharynx or esophagus, lusoria due to deformity of surrounding organs, spastica due to esophagus spasm, oropharyngeal of disability in moving food from mouth to stomach and etc. and symptoms such as dribbling or feeling as if the food has stuck in the esophagus and etc. can appear. Clinically, oropharyngeal dysphagia of difficulty in propulsion of food movement is the most frequent.
Robbins and et el. (2007) reported that dysphagia appears due to damage of complicated nerve—muscle system of muscles related to corticobulbar tract and swallowing. However, recovery in dysphasia after a stroke is due to muscle force recovery of partial swallowing muscle. Accordingly, neuroplastic deformation in priority and additionally increase of muscle force and muscle amount through repetitive exercise is necessary for rehabilitation of dysphagia.
Research conducted by Robbins and et el. (2005, 2007) proves that tongue pressure exercise helps recovery of the size of the tongue and strength, thereby has an effect on the recovery of functional swallowing including oral cavity and esophagus step. Tongue pressure herein is formed during swallowing when the tongue goes up to the palate and squeeze from front to back (Hiiemae, & Palmer, 2003).
For the treatment of dysphagia, oral and facial stimulation, oral and gorge muscle strengthening exercise, oral and facial stimulation for posture correction, strengthening exercise of oral and gorge muscle, reward training treatment using posture correction, heat-tactile stimulation treatment, biofeedback, electric stimulation treatment, surgical treatment and etc. are executed.
However, the afore-mentioned non-surgical method may be difficult to induce interest to patients, hence may reduce rehabilitation efficiency. Further, there are shortcomings that quantitative evaluation of tongue exercise and a third person's guidance is necessary for accurate rehabilitation. In this circumstance, apparatus that improves efficiency by making rehabilitation interesting, participating in voluntary rehabilitation and enabling active and accurate exercise that patients can do by themselves is required.